function compareToSimple_singleFreq(c)

if ~isfield(c,'M')
    error('need to run numerical solver first')
end
if size(c.M,2)>1
    error('just one freq');
end

% grab vales from c
bh      = c.bunHeight;
M       = c.M;
dispAmp = c.dispAmp;
freqs   = c.freqs;
heights = c.heights;
mu      = c.mu;
rho     = c.rho;
L       = c.cupHeight;
a       = c.baseDiameter/2;
EI      = c.E_matrix .* (pi*a^4/4);
omega   = 2 * pi * freqs;
bDif    = interp1(heights,M,bh);
flwSpd  = i * 2 * pi * freqs * dispAmp;
sense   = abs(bDif) / abs(flwSpd)
phase   = (angle(bDif)) / pi * 180


%simple:
x       = bh;
D0      = dispAmp;
delta   = (2 * mu / rho / omega);
s       = a ./ 2^.5 / delta;
g       = 0.577 + log(s);
G       = -g / (g^2 + (pi/4)^2);
d       = D0 * (1 + i) * bh ./ delta;
%q       = 4 * pi * mu * G * d * i *omega;
moment  = - ( (2/3 - 2*i/3) *D0*G*pi * (L-x)^2 * (2*L+x) * mu*omega) / ...
            delta;

v  = -( (1/30 - i/30) * D0*G*pi*bh^2 * (20*L^3 - 10*L^2*bh + bh^3) * mu*omega )/ ...
    ( EI*delta);


sense_v = abs(v) / abs(flwSpd)
phase_v = (angle(v)) / pi * 180

